[Techtoolslist] 9100FT Programmer’s Keyboard

Tony Jones tony at tonyjones.com
Thu Oct 18 10:45:27 EDT 2018


On Thu, Oct 18, 2018, 12:12 AM John Robertson <jrr at flippers.com> wrote:

> I thought the 8031 had an option to boot externally if you tied a leg
> low...
>

Yes, _EA_ but the 8031 is supposed to be ROMless and so pin 31 should
always be low.  On the 8051 it's high to use onboard 4k ROM, low for
external.  Either way I'll check when I have time.  As I said in previous
message its possible it's controlled by one of the 8 dip switches but it
seemed odd the chip was still marked 8031.


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